Every time I let the clutch out to engage, I get a decided 'clunking' sound as the clutch engages. Even when I let the clutch out slowly, at the time of engagement, it consistently makes the sound. It has been doing it for a long time, doesn't seem to be getting worse or affect the drive-ability. It is kind of hard to tell exactly where it is coming from, although somewhere between and including the transmission to final drive.
Clutch and driveshaft splines were inspected (everything was OK) and lubed at about 44K miles, bike now has about 56K miles. I think that the sound started up shortly after the spline lubes. Any ideas? Something to be concerned about?